JPH0389765A - Telephone set - Google Patents

Abstract

PURPOSE:To accumulate a large power to utilize many functions of a subscriber' s set by connecting the primary winding of a transformer to a subscriber line through a capacitance element, and inputting the secondary winding of the transformer to a charging circuit. CONSTITUTION:The charging circuit 2 is connected to the subscriber line connected to a telephone circuit 1 through resistors R1, R2 which have a high resistance value, and the received power is charged in a charging battery B, and is used as power supply for the function excepting the communication of the telephone circuit 1. Further, a circuit in which capacitors C1, C2 and the primary winding of the transformer T are connected in series is connected between two wires of the subscriber line. Then, a call signal from a central office flows in the serial circuit of the capacitors C1, C2 and the primary winding of the transformer T as well, and this current charges the charging battery B through the charging circuit 2. Thus, the larger power is accumulated compared with a case that DC voltage is only charged by a weak current through high impedance elements R1, R2, and more functions as the telephone set can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a telephone set, and more particularly to a telephone set that receives charging current from a subscriber line.

[Conventional technology]

Conventionally, when a telephone requires power for functions other than making calls (display, etc.), a rechargeable battery is used, which is charged with a weak current through a high resistance using the DC voltage (DC48V) supplied to the subscriber line. There were two options: to use a commercial power source, or to use a power source converted to direct current from a commercial power source via an AC adapter.

[Problem to be solved by the invention]

The above-mentioned conventional method of supplying power to telephones has the problem that when using a rechargeable battery that is charged with a weak current, the battery can only provide limited functions because the power that can be supplied by the battery is small. Also, when receiving power from a commercial power source via an AC adapter, it is possible to obtain large amounts of power, so there are no restrictions on the functions that can be provided, but a power line for the AC adapter is required in addition to the subscriber line. However, there is a problem in that there are restrictions on where the telephone can be installed.

[Means to solve the problem]

The telephone of the present invention is a telephone that constantly receives a weak current from a subscriber line through a high impedance element in a charging circuit, stores it, and uses it for purposes other than talking current. The secondary winding of the transformer is connected to the secondary winding of the transformer, and the secondary winding of the transformer is input to the charging circuit.

〔Example〕

FIG. 1 is a circuit diagram of an embodiment of the present invention. In particular, the portion surrounded by the dashed line is the additional circuit according to the present invention.

A charging circuit 2 is connected to a subscriber line connected to the telephone circuit 1 via resistors R1+R2 having a high resistance value. The charging circuit 2 charges a rechargeable battery B with the received power and uses it as a power source for functions of the telephone circuit 1 other than calls. Furthermore, capacitors CI and C2 are connected between the two subscriber lines.
) A circuit in which the primary winding of the transformer T is connected in series, and the secondary winding of the transformer T is connected to the charging circuit 2.

Next, the operation will be explained.

During normal on-hook operation, a 48 V DC current supplied from the telephone office charges the rechargeable battery B via the resistors R, , R and the charging circuit 2. Then, while the phone is ringing,
The call signal (AC75V) from the telephone office is connected to capacitor c.
,, also flows in the series circuit between C2 and the primary winding of the transformer T, and this current charges the rechargeable battery B from the secondary winding of the transformer T via the charging circuit 2.

Next, while the telephone is in use, power is supplied from the rechargeable battery B to the telephone circuit 1 to operate telephone functions other than telephone calls (display, etc.).

〔Effect of the invention〕

As explained above, when a telephone supplies power to a display device, etc. for functions other than calling, the present invention charges the direct current voltage (DC48V) supplied to the subscriber line with a weak current through a high impedance element. Since a larger amount of power can be stored compared to the case where the telephone is only used, the telephone has the effect of being able to provide more functions.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Telephone circuit, 2... Charging circuit, B... Rechargeable battery, C1, C2... Capacitor, R,, R2...
Resistor, T...transformer.

Claims (1)

[Claims] In a telephone that constantly receives and stores a weak current from a subscriber line through a high impedance element in a charging circuit and is used for purposes other than talking current, the primary winding of a transformer is connected to the subscriber line through a capacitive element. and a secondary winding of the transformer is input to the charging circuit.